The Fitchburg-Longsjo Classic may have run its last race. Photo: Mark Johnson

Organizers of the Fitchburg-Longsjo Classic, the second oldest bicycle race in the country, this week cancelled the four-day event scheduled for June 28 to July 1, citing low pre-registration numbers.

The Massachusetts race began in 1960 as a tribute to Fitchburg’s Arthur Longsjo, who in 1956 became the first U.S. athlete to compete in both Winter (speedskating) and Summer (cycling) Olympic games in one year. Longsjo died in a car crash while returning home from winning a race in Quebec. Past winners include Lance Armstrong, Chris Horner, Tyler Hamilton, Davis Phinney, Connie Carpenter, Rebecca Twigg and Evelyn Stevens.

The race expanded to a four-day stage race in 1991, though for 2011 it was planned as a scaled-back, one-day criterium. That event was done-in by a major building fire on the course two weeks before the race, which caused an extended closure of the city’s Main Street. With strong backing from local communities, promoters laid out solid-looking plans for 2012, with revamped stages and four days of racing.

“The response of the community was incredible,” said race committee chair Ed Collier.

The usual bane of race — cash sponsorship — was in place, along with course permits. With a $20,000 prize list for both elite men and women, plus lower race categories, all the ingredients seemed to be there.

But with less than three weeks to go, promoters had less than 160 riders entered across all categories, and pulled the plug.

“It is ironic that we secured more support than ever for this race, in terms of raising money and securing the support of local officials, but we can’t have a world-class event with a dearth of riders.”

Collier cited 550 riders as the break-even point for race financially. With online entry, many competitors wait until the last week — and indeed numerous riders and supporters encouraged the promoters to wait it out, insisting the numbers would come — but ultimately it was a financial risk the promoters were not willing to take.

“This is a heart wrenching decision,” said Collier. He added that any plans for the future are undetermined. But even to longtime supporters of the event, a return after such a cancellation seems highly unlikely.